title: Vasectomy and the risk of prostate cancer.
abstract: OBJECTIVE
  While the weight of evidence shows no association overall between vasectomy and prostate cancer, there has been some suggestion that an association may exist in subgroups, such as men who have a family history of prostate cancer, men who undergo vasectomy at a younger age or when several decades have passed since the procedure. Studies of risk with long latency periods have been hampered by small sample sizes in subgroups since vasectomy only became widely used in the 1960s and generally prostate cancer has a long latency period.
  
  
  METHODS
  We analyzed data from a recent population based case-control study that was designed specifically to address this issue of risk in subgroups. Interviews were completed with 1,001 men diagnosed with prostate cancer from January 1, 2002 through December 31, 2005 in the Seattle-Puget Sound region and in 942 matched control men. Subjects were black and white men between the ages of 35 and 74 years. Data were analyzed using unconditional logistic regression to calculate the OR as an estimate of the relative risk of prostate cancer associated with various vasectomy parameters.
  
  
  RESULTS
  The prevalence of vasectomy was similar in cases and controls (36.2% and 36.1%, respectively, adjusted OR 1.0, 95% CI 0.8-1.2). There were also no associations between prostate cancer and age at vasectomy, years elapsed since vasectomy or calendar year of vasectomy.
  
  
  CONCLUSIONS
  These findings indicate that there is no association between vasectomy and the risk of prostate cancer.
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA. skholt@fhcrc.org
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Holt
authors.forename: Claudia A
authors.initials: CA
authors.lastname: Salinas
authors.forename: Janet L
authors.initials: JL
authors.lastname: Stanford
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000453:epidemiology / Q000209:etiology*; D012307:Risk Factors; D014659:Vasectomy / Q000009:adverse effects*